[Qemu-devel] segfault with VNC and --enable-debug

[Anthony PERARD <anthony.perard@citrix.com>]

Hi,

I found a segfault when I use VNC with qemu compiled with
--enable-debug. Without debug mode, that works fine. The segfault
happen usualy when the debian (guest) is ready to be used, or a little
bit after I'm logged in, in console mode.

Here is few detail:

HEAD
711c212 Merge remote-tracking branch 'stefanha/trivial-patches' into staging

# Configured with: '../configure' '--target-list=i386-softmmu'
'--enable-trace-backend=stderr' '--enable-debug'

Run with:
~/work/qemu/_build-noxen/i386-softmmu/qemu -name debian -vnc
0.0.0.0:0,to=99 -sdl -boot order=c -smp 2,maxcpus=3 -net
nic,vlan=0,macaddr=00:16:3e:26:42:7d,model=rtl8139 -net
tap,vlan=0,ifname=tap8.0,script=no -m 512 -drive
file=/root/vm/vm.img,if=ide,index=0,media=disk,format=raw

And the backtrace:
Program received signal SIGSEGV, Segmentation fault.
0x91fdce94 in ?? ()
(gdb) bt
#0  0x91fdce94 in ?? ()
#1  0x0811f3a5 in vnc_refresh_server_surface (vd=0x8b3f720) at
/local/home/anthony/work/qemu/ui/vnc.c:2419
#2  0x0811f572 in vnc_refresh (opaque=0x8b3f720) at
/local/home/anthony/work/qemu/ui/vnc.c:2453
#3  0x08138ce1 in qemu_run_timers (clock=0x89647d8) at
/local/home/anthony/work/qemu/qemu-timer.c:608
#4  0x08139081 in qemu_run_all_timers () at
/local/home/anthony/work/qemu/qemu-timer.c:726
#5  0x081d7daa in main_loop_wait (nonblocking=1) at
/local/home/anthony/work/qemu/vl.c:1336
#6  0x081d7e65 in main_loop () at /local/home/anthony/work/qemu/vl.c:1377
#7  0x081dca68 in main (argc=18, argv=0xbffff684, envp=0xbffff6d0) at
/local/home/anthony/work/qemu/vl.c:3289
(gdb) up
#1  0x0811f3a5 in vnc_refresh_server_surface (vd=0x8b3f720) at
/local/home/anthony/work/qemu/ui/vnc.c:2419
2419                    if (!test_and_clear_bit((x / 16), vd->guest.dirty[y]))

Regards,

-- 
Anthony PERARD